1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "sehandle.h"
18 #include "Utils.h"
19 #include "Process.h"
20
21 #include <android-base/file.h>
22 #include <android-base/logging.h>
23 #include <android-base/stringprintf.h>
24 #include <cutils/fs.h>
25 #include <cutils/properties.h>
26 #include <private/android_filesystem_config.h>
27 #include <logwrap/logwrap.h>
28
29 #include <mutex>
30 #include <dirent.h>
31 #include <fcntl.h>
32 #include <linux/fs.h>
33 #include <stdlib.h>
34 #include <sys/mount.h>
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 #include <sys/wait.h>
38 #include <sys/statvfs.h>
39
40 #ifndef UMOUNT_NOFOLLOW
41 #define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */
42 #endif
43
44 using android::base::ReadFileToString;
45 using android::base::StringPrintf;
46
47 namespace android {
48 namespace vold {
49
50 security_context_t sBlkidContext = nullptr;
51 security_context_t sBlkidUntrustedContext = nullptr;
52 security_context_t sFsckContext = nullptr;
53 security_context_t sFsckUntrustedContext = nullptr;
54
55 static const char* kBlkidPath = "/system/bin/blkid";
56 static const char* kKeyPath = "/data/misc/vold";
57
58 static const char* kProcFilesystems = "/proc/filesystems";
59
CreateDeviceNode(const std::string & path,dev_t dev)60 status_t CreateDeviceNode(const std::string& path, dev_t dev) {
61 const char* cpath = path.c_str();
62 status_t res = 0;
63
64 char* secontext = nullptr;
65 if (sehandle) {
66 if (!selabel_lookup(sehandle, &secontext, cpath, S_IFBLK)) {
67 setfscreatecon(secontext);
68 }
69 }
70
71 mode_t mode = 0660 | S_IFBLK;
72 if (mknod(cpath, mode, dev) < 0) {
73 if (errno != EEXIST) {
74 PLOG(ERROR) << "Failed to create device node for " << major(dev)
75 << ":" << minor(dev) << " at " << path;
76 res = -errno;
77 }
78 }
79
80 if (secontext) {
81 setfscreatecon(nullptr);
82 freecon(secontext);
83 }
84
85 return res;
86 }
87
DestroyDeviceNode(const std::string & path)88 status_t DestroyDeviceNode(const std::string& path) {
89 const char* cpath = path.c_str();
90 if (TEMP_FAILURE_RETRY(unlink(cpath))) {
91 return -errno;
92 } else {
93 return OK;
94 }
95 }
96
PrepareDir(const std::string & path,mode_t mode,uid_t uid,gid_t gid)97 status_t PrepareDir(const std::string& path, mode_t mode, uid_t uid, gid_t gid) {
98 const char* cpath = path.c_str();
99
100 char* secontext = nullptr;
101 if (sehandle) {
102 if (!selabel_lookup(sehandle, &secontext, cpath, S_IFDIR)) {
103 setfscreatecon(secontext);
104 }
105 }
106
107 int res = fs_prepare_dir(cpath, mode, uid, gid);
108
109 if (secontext) {
110 setfscreatecon(nullptr);
111 freecon(secontext);
112 }
113
114 if (res == 0) {
115 return OK;
116 } else {
117 return -errno;
118 }
119 }
120
ForceUnmount(const std::string & path)121 status_t ForceUnmount(const std::string& path) {
122 const char* cpath = path.c_str();
123 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
124 return OK;
125 }
126 // Apps might still be handling eject request, so wait before
127 // we start sending signals
128 sleep(5);
129
130 Process::killProcessesWithOpenFiles(cpath, SIGINT);
131 sleep(5);
132 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
133 return OK;
134 }
135
136 Process::killProcessesWithOpenFiles(cpath, SIGTERM);
137 sleep(5);
138 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
139 return OK;
140 }
141
142 Process::killProcessesWithOpenFiles(cpath, SIGKILL);
143 sleep(5);
144 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
145 return OK;
146 }
147
148 return -errno;
149 }
150
KillProcessesUsingPath(const std::string & path)151 status_t KillProcessesUsingPath(const std::string& path) {
152 const char* cpath = path.c_str();
153 if (Process::killProcessesWithOpenFiles(cpath, SIGINT) == 0) {
154 return OK;
155 }
156 sleep(5);
157
158 if (Process::killProcessesWithOpenFiles(cpath, SIGTERM) == 0) {
159 return OK;
160 }
161 sleep(5);
162
163 if (Process::killProcessesWithOpenFiles(cpath, SIGKILL) == 0) {
164 return OK;
165 }
166 sleep(5);
167
168 // Send SIGKILL a second time to determine if we've
169 // actually killed everyone with open files
170 if (Process::killProcessesWithOpenFiles(cpath, SIGKILL) == 0) {
171 return OK;
172 }
173 PLOG(ERROR) << "Failed to kill processes using " << path;
174 return -EBUSY;
175 }
176
BindMount(const std::string & source,const std::string & target)177 status_t BindMount(const std::string& source, const std::string& target) {
178 if (::mount(source.c_str(), target.c_str(), "", MS_BIND, NULL)) {
179 PLOG(ERROR) << "Failed to bind mount " << source << " to " << target;
180 return -errno;
181 }
182 return OK;
183 }
184
readMetadata(const std::string & path,std::string & fsType,std::string & fsUuid,std::string & fsLabel,bool untrusted)185 static status_t readMetadata(const std::string& path, std::string& fsType,
186 std::string& fsUuid, std::string& fsLabel, bool untrusted) {
187 fsType.clear();
188 fsUuid.clear();
189 fsLabel.clear();
190
191 std::vector<std::string> cmd;
192 cmd.push_back(kBlkidPath);
193 cmd.push_back("-c");
194 cmd.push_back("/dev/null");
195 cmd.push_back("-s");
196 cmd.push_back("TYPE");
197 cmd.push_back("-s");
198 cmd.push_back("UUID");
199 cmd.push_back("-s");
200 cmd.push_back("LABEL");
201 cmd.push_back(path);
202
203 std::vector<std::string> output;
204 status_t res = ForkExecvp(cmd, output, untrusted ? sBlkidUntrustedContext : sBlkidContext);
205 if (res != OK) {
206 LOG(WARNING) << "blkid failed to identify " << path;
207 return res;
208 }
209
210 char value[128];
211 for (auto line : output) {
212 // Extract values from blkid output, if defined
213 const char* cline = line.c_str();
214 char* start = strstr(cline, "TYPE=");
215 if (start != nullptr && sscanf(start + 5, "\"%127[^\"]\"", value) == 1) {
216 fsType = value;
217 }
218
219 start = strstr(cline, "UUID=");
220 if (start != nullptr && sscanf(start + 5, "\"%127[^\"]\"", value) == 1) {
221 fsUuid = value;
222 }
223
224 start = strstr(cline, "LABEL=");
225 if (start != nullptr && sscanf(start + 6, "\"%127[^\"]\"", value) == 1) {
226 fsLabel = value;
227 }
228 }
229
230 return OK;
231 }
232
ReadMetadata(const std::string & path,std::string & fsType,std::string & fsUuid,std::string & fsLabel)233 status_t ReadMetadata(const std::string& path, std::string& fsType,
234 std::string& fsUuid, std::string& fsLabel) {
235 return readMetadata(path, fsType, fsUuid, fsLabel, false);
236 }
237
ReadMetadataUntrusted(const std::string & path,std::string & fsType,std::string & fsUuid,std::string & fsLabel)238 status_t ReadMetadataUntrusted(const std::string& path, std::string& fsType,
239 std::string& fsUuid, std::string& fsLabel) {
240 return readMetadata(path, fsType, fsUuid, fsLabel, true);
241 }
242
ForkExecvp(const std::vector<std::string> & args)243 status_t ForkExecvp(const std::vector<std::string>& args) {
244 return ForkExecvp(args, nullptr);
245 }
246
ForkExecvp(const std::vector<std::string> & args,security_context_t context)247 status_t ForkExecvp(const std::vector<std::string>& args, security_context_t context) {
248 size_t argc = args.size();
249 char** argv = (char**) calloc(argc, sizeof(char*));
250 for (size_t i = 0; i < argc; i++) {
251 argv[i] = (char*) args[i].c_str();
252 if (i == 0) {
253 LOG(VERBOSE) << args[i];
254 } else {
255 LOG(VERBOSE) << " " << args[i];
256 }
257 }
258
259 if (setexeccon(context)) {
260 LOG(ERROR) << "Failed to setexeccon";
261 abort();
262 }
263 status_t res = android_fork_execvp(argc, argv, NULL, false, true);
264 if (setexeccon(nullptr)) {
265 LOG(ERROR) << "Failed to setexeccon";
266 abort();
267 }
268
269 free(argv);
270 return res;
271 }
272
ForkExecvp(const std::vector<std::string> & args,std::vector<std::string> & output)273 status_t ForkExecvp(const std::vector<std::string>& args,
274 std::vector<std::string>& output) {
275 return ForkExecvp(args, output, nullptr);
276 }
277
ForkExecvp(const std::vector<std::string> & args,std::vector<std::string> & output,security_context_t context)278 status_t ForkExecvp(const std::vector<std::string>& args,
279 std::vector<std::string>& output, security_context_t context) {
280 std::string cmd;
281 for (size_t i = 0; i < args.size(); i++) {
282 cmd += args[i] + " ";
283 if (i == 0) {
284 LOG(VERBOSE) << args[i];
285 } else {
286 LOG(VERBOSE) << " " << args[i];
287 }
288 }
289 output.clear();
290
291 if (setexeccon(context)) {
292 LOG(ERROR) << "Failed to setexeccon";
293 abort();
294 }
295 FILE* fp = popen(cmd.c_str(), "r");
296 if (setexeccon(nullptr)) {
297 LOG(ERROR) << "Failed to setexeccon";
298 abort();
299 }
300
301 if (!fp) {
302 PLOG(ERROR) << "Failed to popen " << cmd;
303 return -errno;
304 }
305 char line[1024];
306 while (fgets(line, sizeof(line), fp) != nullptr) {
307 LOG(VERBOSE) << line;
308 output.push_back(std::string(line));
309 }
310 if (pclose(fp) != 0) {
311 PLOG(ERROR) << "Failed to pclose " << cmd;
312 return -errno;
313 }
314
315 return OK;
316 }
317
ForkExecvpAsync(const std::vector<std::string> & args)318 pid_t ForkExecvpAsync(const std::vector<std::string>& args) {
319 size_t argc = args.size();
320 char** argv = (char**) calloc(argc + 1, sizeof(char*));
321 for (size_t i = 0; i < argc; i++) {
322 argv[i] = (char*) args[i].c_str();
323 if (i == 0) {
324 LOG(VERBOSE) << args[i];
325 } else {
326 LOG(VERBOSE) << " " << args[i];
327 }
328 }
329
330 pid_t pid = fork();
331 if (pid == 0) {
332 close(STDIN_FILENO);
333 close(STDOUT_FILENO);
334 close(STDERR_FILENO);
335
336 if (execvp(argv[0], argv)) {
337 PLOG(ERROR) << "Failed to exec";
338 }
339
340 _exit(1);
341 }
342
343 if (pid == -1) {
344 PLOG(ERROR) << "Failed to exec";
345 }
346
347 free(argv);
348 return pid;
349 }
350
ReadRandomBytes(size_t bytes,std::string & out)351 status_t ReadRandomBytes(size_t bytes, std::string& out) {
352 out.clear();
353
354 int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOFOLLOW));
355 if (fd == -1) {
356 return -errno;
357 }
358
359 char buf[BUFSIZ];
360 size_t n;
361 while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], std::min(sizeof(buf), bytes)))) > 0) {
362 out.append(buf, n);
363 bytes -= n;
364 }
365 close(fd);
366
367 if (bytes == 0) {
368 return OK;
369 } else {
370 return -EIO;
371 }
372 }
373
HexToStr(const std::string & hex,std::string & str)374 status_t HexToStr(const std::string& hex, std::string& str) {
375 str.clear();
376 bool even = true;
377 char cur = 0;
378 for (size_t i = 0; i < hex.size(); i++) {
379 int val = 0;
380 switch (hex[i]) {
381 case ' ': case '-': case ':': continue;
382 case 'f': case 'F': val = 15; break;
383 case 'e': case 'E': val = 14; break;
384 case 'd': case 'D': val = 13; break;
385 case 'c': case 'C': val = 12; break;
386 case 'b': case 'B': val = 11; break;
387 case 'a': case 'A': val = 10; break;
388 case '9': val = 9; break;
389 case '8': val = 8; break;
390 case '7': val = 7; break;
391 case '6': val = 6; break;
392 case '5': val = 5; break;
393 case '4': val = 4; break;
394 case '3': val = 3; break;
395 case '2': val = 2; break;
396 case '1': val = 1; break;
397 case '0': val = 0; break;
398 default: return -EINVAL;
399 }
400
401 if (even) {
402 cur = val << 4;
403 } else {
404 cur += val;
405 str.push_back(cur);
406 cur = 0;
407 }
408 even = !even;
409 }
410 return even ? OK : -EINVAL;
411 }
412
413 static const char* kLookup = "0123456789abcdef";
414
StrToHex(const std::string & str,std::string & hex)415 status_t StrToHex(const std::string& str, std::string& hex) {
416 hex.clear();
417 for (size_t i = 0; i < str.size(); i++) {
418 hex.push_back(kLookup[(str[i] & 0xF0) >> 4]);
419 hex.push_back(kLookup[str[i] & 0x0F]);
420 }
421 return OK;
422 }
423
NormalizeHex(const std::string & in,std::string & out)424 status_t NormalizeHex(const std::string& in, std::string& out) {
425 std::string tmp;
426 if (HexToStr(in, tmp)) {
427 return -EINVAL;
428 }
429 return StrToHex(tmp, out);
430 }
431
GetFreeBytes(const std::string & path)432 uint64_t GetFreeBytes(const std::string& path) {
433 struct statvfs sb;
434 if (statvfs(path.c_str(), &sb) == 0) {
435 return (uint64_t)sb.f_bfree * sb.f_bsize;
436 } else {
437 return -1;
438 }
439 }
440
441 // TODO: borrowed from frameworks/native/libs/diskusage/ which should
442 // eventually be migrated into system/
stat_size(struct stat * s)443 static int64_t stat_size(struct stat *s) {
444 int64_t blksize = s->st_blksize;
445 // count actual blocks used instead of nominal file size
446 int64_t size = s->st_blocks * 512;
447
448 if (blksize) {
449 /* round up to filesystem block size */
450 size = (size + blksize - 1) & (~(blksize - 1));
451 }
452
453 return size;
454 }
455
456 // TODO: borrowed from frameworks/native/libs/diskusage/ which should
457 // eventually be migrated into system/
calculate_dir_size(int dfd)458 int64_t calculate_dir_size(int dfd) {
459 int64_t size = 0;
460 struct stat s;
461 DIR *d;
462 struct dirent *de;
463
464 d = fdopendir(dfd);
465 if (d == NULL) {
466 close(dfd);
467 return 0;
468 }
469
470 while ((de = readdir(d))) {
471 const char *name = de->d_name;
472 if (fstatat(dfd, name, &s, AT_SYMLINK_NOFOLLOW) == 0) {
473 size += stat_size(&s);
474 }
475 if (de->d_type == DT_DIR) {
476 int subfd;
477
478 /* always skip "." and ".." */
479 if (name[0] == '.') {
480 if (name[1] == 0)
481 continue;
482 if ((name[1] == '.') && (name[2] == 0))
483 continue;
484 }
485
486 subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
487 if (subfd >= 0) {
488 size += calculate_dir_size(subfd);
489 }
490 }
491 }
492 closedir(d);
493 return size;
494 }
495
GetTreeBytes(const std::string & path)496 uint64_t GetTreeBytes(const std::string& path) {
497 int dirfd = open(path.c_str(), O_DIRECTORY, O_RDONLY);
498 if (dirfd < 0) {
499 PLOG(WARNING) << "Failed to open " << path;
500 return -1;
501 } else {
502 uint64_t res = calculate_dir_size(dirfd);
503 close(dirfd);
504 return res;
505 }
506 }
507
IsFilesystemSupported(const std::string & fsType)508 bool IsFilesystemSupported(const std::string& fsType) {
509 std::string supported;
510 if (!ReadFileToString(kProcFilesystems, &supported)) {
511 PLOG(ERROR) << "Failed to read supported filesystems";
512 return false;
513 }
514 return supported.find(fsType + "\n") != std::string::npos;
515 }
516
WipeBlockDevice(const std::string & path)517 status_t WipeBlockDevice(const std::string& path) {
518 status_t res = -1;
519 const char* c_path = path.c_str();
520 unsigned long nr_sec = 0;
521 unsigned long long range[2];
522
523 int fd = TEMP_FAILURE_RETRY(open(c_path, O_RDWR | O_CLOEXEC));
524 if (fd == -1) {
525 PLOG(ERROR) << "Failed to open " << path;
526 goto done;
527 }
528
529 if ((ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
530 PLOG(ERROR) << "Failed to determine size of " << path;
531 goto done;
532 }
533
534 range[0] = 0;
535 range[1] = (unsigned long long) nr_sec * 512;
536
537 LOG(INFO) << "About to discard " << range[1] << " on " << path;
538 if (ioctl(fd, BLKDISCARD, &range) == 0) {
539 LOG(INFO) << "Discard success on " << path;
540 res = 0;
541 } else {
542 PLOG(ERROR) << "Discard failure on " << path;
543 }
544
545 done:
546 close(fd);
547 return res;
548 }
549
isValidFilename(const std::string & name)550 static bool isValidFilename(const std::string& name) {
551 if (name.empty() || (name == ".") || (name == "..")
552 || (name.find('/') != std::string::npos)) {
553 return false;
554 } else {
555 return true;
556 }
557 }
558
BuildKeyPath(const std::string & partGuid)559 std::string BuildKeyPath(const std::string& partGuid) {
560 return StringPrintf("%s/expand_%s.key", kKeyPath, partGuid.c_str());
561 }
562
BuildDataSystemLegacyPath(userid_t userId)563 std::string BuildDataSystemLegacyPath(userid_t userId) {
564 return StringPrintf("%s/system/users/%u", BuildDataPath(nullptr).c_str(), userId);
565 }
566
BuildDataSystemCePath(userid_t userId)567 std::string BuildDataSystemCePath(userid_t userId) {
568 return StringPrintf("%s/system_ce/%u", BuildDataPath(nullptr).c_str(), userId);
569 }
570
BuildDataSystemDePath(userid_t userId)571 std::string BuildDataSystemDePath(userid_t userId) {
572 return StringPrintf("%s/system_de/%u", BuildDataPath(nullptr).c_str(), userId);
573 }
574
BuildDataMiscLegacyPath(userid_t userId)575 std::string BuildDataMiscLegacyPath(userid_t userId) {
576 return StringPrintf("%s/misc/user/%u", BuildDataPath(nullptr).c_str(), userId);
577 }
578
BuildDataMiscCePath(userid_t userId)579 std::string BuildDataMiscCePath(userid_t userId) {
580 return StringPrintf("%s/misc_ce/%u", BuildDataPath(nullptr).c_str(), userId);
581 }
582
BuildDataMiscDePath(userid_t userId)583 std::string BuildDataMiscDePath(userid_t userId) {
584 return StringPrintf("%s/misc_de/%u", BuildDataPath(nullptr).c_str(), userId);
585 }
586
587 // Keep in sync with installd (frameworks/native/cmds/installd/utils.h)
BuildDataProfilesDePath(userid_t userId)588 std::string BuildDataProfilesDePath(userid_t userId) {
589 return StringPrintf("%s/misc/profiles/cur/%u", BuildDataPath(nullptr).c_str(), userId);
590 }
591
BuildDataProfilesForeignDexDePath(userid_t userId)592 std::string BuildDataProfilesForeignDexDePath(userid_t userId) {
593 std::string profiles_path = BuildDataProfilesDePath(userId);
594 return StringPrintf("%s/foreign-dex", profiles_path.c_str());
595 }
596
BuildDataPath(const char * volumeUuid)597 std::string BuildDataPath(const char* volumeUuid) {
598 // TODO: unify with installd path generation logic
599 if (volumeUuid == nullptr) {
600 return "/data";
601 } else {
602 CHECK(isValidFilename(volumeUuid));
603 return StringPrintf("/mnt/expand/%s", volumeUuid);
604 }
605 }
606
BuildDataMediaCePath(const char * volumeUuid,userid_t userId)607 std::string BuildDataMediaCePath(const char* volumeUuid, userid_t userId) {
608 // TODO: unify with installd path generation logic
609 std::string data(BuildDataPath(volumeUuid));
610 return StringPrintf("%s/media/%u", data.c_str(), userId);
611 }
612
BuildDataUserCePath(const char * volumeUuid,userid_t userId)613 std::string BuildDataUserCePath(const char* volumeUuid, userid_t userId) {
614 // TODO: unify with installd path generation logic
615 std::string data(BuildDataPath(volumeUuid));
616 if (volumeUuid == nullptr) {
617 if (userId == 0) {
618 return StringPrintf("%s/data", data.c_str());
619 } else {
620 return StringPrintf("%s/user/%u", data.c_str(), userId);
621 }
622 } else {
623 return StringPrintf("%s/user/%u", data.c_str(), userId);
624 }
625 }
626
BuildDataUserDePath(const char * volumeUuid,userid_t userId)627 std::string BuildDataUserDePath(const char* volumeUuid, userid_t userId) {
628 // TODO: unify with installd path generation logic
629 std::string data(BuildDataPath(volumeUuid));
630 return StringPrintf("%s/user_de/%u", data.c_str(), userId);
631 }
632
GetDevice(const std::string & path)633 dev_t GetDevice(const std::string& path) {
634 struct stat sb;
635 if (stat(path.c_str(), &sb)) {
636 PLOG(WARNING) << "Failed to stat " << path;
637 return 0;
638 } else {
639 return sb.st_dev;
640 }
641 }
642
DefaultFstabPath()643 std::string DefaultFstabPath() {
644 char hardware[PROPERTY_VALUE_MAX];
645 property_get("ro.hardware", hardware, "");
646 return StringPrintf("/fstab.%s", hardware);
647 }
648
SaneReadLinkAt(int dirfd,const char * path,char * buf,size_t bufsiz)649 status_t SaneReadLinkAt(int dirfd, const char* path, char* buf, size_t bufsiz) {
650 ssize_t len = readlinkat(dirfd, path, buf, bufsiz);
651 if (len < 0) {
652 return -1;
653 } else if (len == (ssize_t) bufsiz) {
654 return -1;
655 } else {
656 buf[len] = '\0';
657 return 0;
658 }
659 }
660
ScopedFd(int fd)661 ScopedFd::ScopedFd(int fd) : fd_(fd) {}
662
~ScopedFd()663 ScopedFd::~ScopedFd() {
664 close(fd_);
665 }
666
ScopedDir(DIR * dir)667 ScopedDir::ScopedDir(DIR* dir) : dir_(dir) {}
668
~ScopedDir()669 ScopedDir::~ScopedDir() {
670 if (dir_ != nullptr) {
671 closedir(dir_);
672 }
673 }
674
IsRunningInEmulator()675 bool IsRunningInEmulator() {
676 return property_get_bool("ro.kernel.qemu", 0);
677 }
678
679 } // namespace vold
680 } // namespace android
681